Device for locating concealed conductors.



F. j. GREGORY.

DEVICE FOR LOCATING CONCEALED CONDUCTORS.

APPucAnou FILED Aue.2s, 1915.

Patented Jan. 16, 1917.

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Illia FRANK J. GREGORY, 0F NEW YORK, N. Y.

DEVICE FOR LOCATING CONCEALED CONDUCTORS.

Specification of Letters Patent.

Patented J an. 16, 1917.

Application filed August 26, 1915. Serial No. 47,419.

To all 'whom t may concern: v

Be it known that I, FRANK J. GREGORY, a citizen 'of the United States, and a resident of New York city, in the county of' Bronx and State of New York, have invented certain new and useful Improvements in Devices for Locating Concealed Conductors, of which the following is a specification.

This invention relates to apparatus for loeating or indicating the presence of a line of pipe or metallic conductor of electricity such as copper wires, that are concealed or embodied in the 'earth or in the walls'or partitions of a building.

The object of the present invention is to provide means that by simply causing aV special form of current to traverse the concealed pipe or conductor, and bringing a detector member in the vicinity of the pipe or wire, an audible signalr will b'e produced upon the locator being' placed in a certain position relative to the pipe or wire, especially where the conductor is buried in the ground and removed aconsiderable distance from the surface.

In the accompanying drawing illustratin one embodiment of my invention, Figure 1 shows in section, partly in elevation, the means for producing the special form of current. Fig. 2 is a side elevation of the detec tor with the cover removed. Fig. 3 is a cross section of the detector, indicating also the receiver; and Fig. 4 is a diagraml showing the use of the apparatus. y

The apparatus consists of anv induction device for producing a high frequency current of considerable volume, that is in circuit with a generator such as a battery of not less than 6 volts; which circuit is attached to the pipe'or conductor at two approximately remote points, so that the special current is caused to flow through the pipe or wire whose location is to be discovered. As shown I provide an induction coil 1, comprising a core 2 that may vbe the usual soft iron wires. This core or cylindrical form may have the usual insulating covering', such as a fiber tube 3. Around this is wound the primary coil 4, that is shown as comprising two layers' of wire such as No. 14 copper wire. A fiber tube 5 is placed on the primary for insulation, and on` this is wound.

two layers of No. 18. copper wire forming the secondary coil 6. The primary coil has one end connected by wire 7 witha. battery 8. The other end 9 of the primary coil is connected with a suitable interrupter, such as that employed with induction coils. As shown I provide a spring arm 10 located adyacent one end of the core 2, which arm is of 1ron or steel to be attracted by the core when magnetized; and this arm10 I connect directly to the end 9 of the primary coil. In its normal'position the arm 10 is in contact with a screw ,11 carried by upright arm 12 and the contacting portions ofthe screw and arm 10 are preferably of platinum to withstand the sparking effect. The screw or arm 12 is connected with the other terminal of the battery 8. When the circuity is complete through the battery, the core will be' magnetized by the primary 'coil and attract v the arm 10. This will be moved away from the screw and break the' circuit, that will demagnetize the core. The spring arm 10 will then move backto again make the circuit, and this arm will thus be very rapidly vibrated, as is usual with induction coils. lIf desired the usual condenser 13 may be employed in a shunt around the spark gap, as is customary with induction coils. By this means the secondary coil will have a current induced therein of very high frequency, but of considerable volume amperage. respect the form of co-il I employ diifers from the lusual spark coil, as the latter has In this the secondary of very much finer wire than 14, i... which is placed a core 175 of magnetic material, such as iron .wi-res or very'small iron filings. Around this core that is 4shown of cylindrical form, I place' a coil 16, prefJ erably of copper wire of about No.l 24 gage, which coil is of considerable llength such as about 15.0 feet of the wire. The core and the coil, with their usual insulation, as

ing 14, and .are of cylindrical form. .The casing is preferably of woodl or .other insulating material, and is provided with terlminal posts 17 and 18, connected with the iof.

A shown, occupy the central portion of the casextremities of the coil 16 respectively.

These terminals I .connect with the termi- 22 leads V'into a house 23. The coil l isv shown as having one secondary terminal 24 connected with the street main at a hydrant or plug' 25. The other secondary wire 26 is shown as connectedwith a faucet 27 in the rhouse. rent induced in the secondary will flow be- From' this it will result that'the curtween the plug 25 and the faucet 27, through 'the pipe 2l and house pipe 22. To locate the pipe between these two points, the locating device 14 is carried by theoperator with f the receiver placed to the ear, and the casing 1'4 is brought into proximity to this pipe traversed by the current, and the casing is turned and shifteduntil its plane, perpen- Y dicular to the axis of the co vcoincide with the pipe at its nearest locawill lessen or cease entirely.

S. caused to tion to the casing. When thisl is done a very distinct sound or buzzing is produced in the receiver that will indicate the location ofthe pipe. The casing 14 isthen carried along and will serve tofollow the line of the pipe, because vas soon as the casing is movedpout of the plane of the pipe the sound that the casing must be moved to another manner when' embedded in a wall or partilocation and that the pipe changes its direction. The pipe can then be traced, whether buried inythe ground, or in lthe street, or

whetherconcealed inthe walls or partitionsv anywhere vin the building. p It will be y understood that a concealed electric wire can be discovered in the same tion, or even when buried in a conduit in the ground. It is only necessary to connect This vmeans then bring the locating device so that its plane will coincide with that Iof the conductor through which the interrupted current is caused to flow.

It will be further understood that my apparatus lcan be used to detect separately a water pipe concealed in aI wall, even though it should be in proximity to other iron objects, such as beams or structural iron work,

Eor iron casings containing electric wires.

Only the particular type of conductor through which my form of lhigh frequency 4current is flowing, will affect the locating device toproduce the sound inthe receiver, and thefother `iron bodies or ob re more or less m gnetic, will rece1ver. l*

It will be also understood that my ap'- paratus does not depend upon any nice windings or any differential coils, and does not have to be tuned to respond to any particular current or coil.

Having thus described my invention, what I claim is: y

Apparatus for locating concealed conductive material, comprising an induction coil having both the primary and the secondary windings of a few turns of comparatively large wires, in connection with an interrupter whereby to induce a high frequency current of large amperage, and a detector device consistingof a locating member hav-v ing a magnetic core surrounded by a coil of considerable length of ne Wire that -is in closed circuit with a telephone receiver, whereby upon bringing the locator with the plane of its coil parallel o'r coincident with the concealed conductor that is traversed by said induced current the receiver will be caused to sound.

FRANK J. GREGORY.

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